1. Field of the Invention
The present invention relates to a hydrogen generator supplier and an electric vehicle. More specifically the invention pertains to a hydrogen generator supplier that reforms a crude fuel to generate a hydrogen rich gas, enhances the purity of the hydrogen rich gas to produce hydrogen, and feeds a supply of hydrogen thus produced to an electric vehicle. The invention also pertains to an electric vehicle that receives the supply of hydrogen fed from the hydrogen generator supplier and carries out power generation with fuel cells using the supply of hydrogen as a gaseous fuel, so as to obtain a driving force of the vehicle.
2. Discussion of the Background
A variety of electric vehicles have been known, which are provided with fuel cells as a power source for obtaining the driving force of the vehicle and are loaded with hydrogen as a gaseous fuel to carry out the power generation with the fuel cells or a crude fuel for generating the hydrogen. Hydrogen is mounted on the electric vehicle, for example, by charging hydrogen as a compressed gas in a tank or by making hydrogen absorbed into a hydrogen storage alloy. Since the hydrogen of an extremely high purity is fed as the gaseous fuel to the electrodes in the fuel cells, the electric vehicle with hydrogen mounted thereon has a favorably high efficiency of power generation in the operation of the fuel cells. This allows reduction in size of the fuel cells. The use of hydrogen having an extremely high purity effectively prevents toxic substances from being produced in the course of the variety of reactions proceeding in the electric vehicle. The drive of the electric vehicle thus effects the environmental protection.
A known electric vehicle with the crude fuel for producing hydrogen mounted thereon uses a hydrocarbon, such as methanol, as the crude fuel and includes a reformer that carries out the reforming reactions for reforming the crude fuel and producing a hydrogen rich gas (for example, JAPANESE PATENT LAID-OPEN GAZETTE No. 2-174503). Especially in the case where a liquid fuel, such as methanol, is used for the crude fuel, the electric vehicle with the crude fuel and the reformer mounted thereon advantageously extends the possible driving distance of the electric vehicle by one supply of fuel, compared with the case in which a gaseous fuel is used for the crude fuel. The crude material like hydrocarbons is more easily handled and safer for transport than the gaseous hydrogen.
A major problem of the electric vehicle with hydrogen mounted thereon as the fuel is the difficulty in widely distributing and increasing the availability of hydrogen that is stored in the gaseous form in a tank or absorbed in the hydrogen storage alloy. This is the bottleneck for spreading the electric vehicle with fuel cells that use hydrogen as the fuel. It is especially difficult to handle the gaseous hydrogen. There are lots of problems to be solved to enable a large mass of gaseous hydrogen to be readily transported and stored. The use of the hydrogen storage alloy for the transport and storage of hydrogen facilitates the handling, but the known hydrogen storage alloys are all rare metals and extremely expensive. The method of using the hydrogen storage alloy for transport and storage of hydrogen is thus not practical. When any method is applied for transport and storage of hydrogen, it is required to newly found a stable distribution system of hydrogen, in order to enable a supply of hydrogen to be directly fed as the fuel to the electric vehicle.
In the case where a hydrocarbon, such as methanol, is mounted as the crude fuel on the electric vehicle, trace amounts of toxic substances like carbon monoxide and nitrogen oxides occur in the process of reforming the crude fuel. Especially carbon monoxide not only causes the environmental pollution but adheres to the catalyst included in the fuel cells to inhibit the cell reactions. In the electric vehicle that runs while reforming the crude fuel in the reformer, it is required to regulate the operating conditions of the fuel cells and the reformer according to the magnitude of loading (the driving state) and vary the quantity of fuel supplied to the fuel cells and the quantity of power generation in the fuel cells. This undesirably complicates the control procedure. The structure of regulating the operating conditions of the reformer according to the magnitude of loading may not cause the reforming reactions to proceed at the optimum efficiency in the reformer. This results in wasting the energy. A specific amount of carbon dioxide is produced in the course of the reforming reactions of the crude fuel. In the case where a hydrogen rich gas containing the specific amount of carbon dioxide is used as the gaseous fuel, the efficiency of the electrochemical reactions in the fuel cells may be undesirably lowered, compared with the case in which hydrogen of a high purity is used as the gaseous fuel.